PT Closes and reopens every session at opening

[veet]

Not sure what I may be doing wrong, but each and every session i reopen throws the error:

"the I/O Layout of the Audio hardware has been changed by another application. Pro Tools will now close and re-open the session in order to update to the new settings. Do you want to save the session before closing?"

Either option Y/N chosen, it closes, reopens, closes and reopens again. Yes, twice. EVERY SINGLE SESSION. No other application has touched the hardware or the session. I save repeatedly and when exiting PT. What causes this and how do I make it stop?

thanks,
Veet